CN220138474U - Composite cover plate, battery monomer, power battery and electricity utilization device - Google Patents

Abstract

The utility model discloses a composite cover plate, a battery monomer, a power battery and an electric device, wherein the composite cover plate comprises a cover plate substrate and a metal connecting piece, and a pole is arranged on the cover plate substrate; the metal connecting piece is connected with the cover plate substrate and provided with an outer peripheral surface which surrounds the cover plate substrate; the outer peripheral surface of the metal connecting piece is used for coating tab glue, and the tab glue is used for being connected with the aluminum plastic film in a hot melting mode. The composite cover plate, the battery monomer, the power battery and the power device can improve the charge transfer efficiency in the charge and discharge process while guaranteeing the multiplying power performance of the battery, and are beneficial to high-current charge and discharge.

Description

Composite cover plate, battery monomer, power battery and electricity utilization device

Technical Field

The utility model relates to the technical field of power batteries, in particular to a composite cover plate, a battery monomer, a power battery and an electric device.

Background

With the rapid development of new energy industry, the new energy automobile field shows a vigorous development trend. The power battery is used as a key component of the new energy automobile, and the performance of the power battery directly influences the performance of the new energy automobile. The lithium ion battery is a secondary battery which realizes charge and discharge by transferring lithium ions between the anode and the cathode, has the advantages of small volume, high energy density, long cycle life and the like, and is widely applied to the fields of 3C and power batteries at present.

Existing lithium ion batteries generally include a battery housing, a cell body, a closure member, and a quantity of electrolyte solution injected into the battery housing. According to the different battery forms and packaging modes, lithium ion batteries are mainly divided into square batteries, cylindrical batteries and soft package batteries. At present, the domestic power battery field is mainly square batteries and soft package batteries.

In prismatic cells, the closure member is typically a cover plate, which is placed in the cell housing during assembly and then connected to the cell housing by a laser welding process to effect a seal to the cell body. The cover plate is used as a welding seal, and is also provided with a pole, an explosion-proof valve, a liquid injection hole and other structures, wherein the pole is used for conducting current, the explosion-proof valve is used as a pressure relief device when the secondary reaction inside the battery generates excessive gas, the liquid injection hole is a channel for injecting electrolyte, and a sealing nail is welded at the liquid injection hole to seal the liquid injection hole after the electrolyte is injected. In order to guarantee the sealing welding of apron, can reserve certain thickness space in the battery case generally, consequently, compare in the inside negative pressure state that keeps of soft packet of battery electric core body, square battery lacks external pressure in the charging process, leads to counterpoint laminating between positive, the negative pole piece not inseparable, is unfavorable for heavy current charge and discharge, in addition, through annotating liquid Kong Zhuye, compare in soft packet of battery annotate the liquid process time consuming longer, often need twice annotate liquid just can satisfy square battery to the quantity demand of electrolyte.

In the soft-pack battery, the battery case is usually an aluminum plastic film, and the battery core body is sealed by utilizing a hot-melt layer (CPP) of an inner layer of the aluminum plastic film and tab glue on the tab. Compared with square batteries, the soft package battery is simpler in structure, welded lugs are used as diversion channels, and structures such as liquid injection holes and explosion-proof valves are not needed. However, the tab of the soft-packaged battery is generally in a light and thin straight structure, the cross-sectional area and the overcurrent capacity of the tab are limited, and the tab can generate excessive heat when high-current charge and discharge are carried out, so that the potential safety hazard is large, and the performance of the battery multiplying power is not facilitated. The aluminum plastic film pit punching design is required to be adopted in the assembly of the soft package battery, the pit punching depth of the aluminum plastic film is limited, the thickness of the battery core body cannot exceed 15mm, otherwise, the risks of failure and poor sealing of the aluminum plastic film are caused, and the thickness limitation of the battery core body is also a key problem affecting the further application of the current soft package battery; in addition, the welding end of the soft package battery needs to occupy a part of space in the length direction of the battery, so that the volume utilization rate of the battery is reduced.

Disclosure of Invention

In order to overcome the defects, the utility model aims to provide the composite cover plate, the battery cell, the power battery and the power device, which can improve the charge transfer efficiency in the charge and discharge process and facilitate the charge and discharge of large current while ensuring the multiplying power performance of the battery.

In order to achieve the above purpose, one of the technical schemes adopted by the utility model is as follows: a composite cover plate, comprising

A cover plate substrate provided with a pole;

the metal connecting piece is connected with the cover plate substrate and provided with an outer peripheral surface which surrounds the cover plate substrate; the outer peripheral surface of the metal connecting piece is used for coating tab glue, and the tab glue is used for being connected with the aluminum plastic film in a hot melting mode.

The composite cover plate has the beneficial effects that:

1. the composite cover plate provided by the utility model can have the advantages of square batteries and soft package batteries when being applied to battery monomers through the matching of the cover plate substrate and the metal connecting piece: the electrode post on the cover plate substrate is connected with the battery core, so that the electrode post is used as a current conducting channel, the overcurrent capacity of high-current charge and discharge is ensured, and the high-rate performance of the battery is further ensured; the tab glue on the metal connecting piece is connected with the aluminum plastic film in a hot melting way, so that the inside of the aluminum plastic film can be kept in a negative pressure state after the battery cell is assembled, the positive electrode plate and the negative electrode plate of the battery cell can be tightly attached, charge transfer in a charging and discharging process is facilitated, and then ion migration among the electrode plates of the battery cell and a high-current charging and discharging effect are improved;

2. compared with the traditional soft-package battery, the utility model seals the aluminum plastic film through the outer peripheral surface of the composite cover plate, so that the aluminum plastic film does not need to be punched, the thickness of the battery core of the soft-package battery is prevented from being limited by the depth of the punching pit of the aluminum plastic film, and the processing of the thick-size battery core is realized; the pole column on the composite cover plate is used as a current conducting channel, so that the problem of insufficient overcurrent of the pole lugs of the soft package battery is solved; in addition, the pole is arranged on the cover plate substrate, and the aluminum plastic film is thermally fused on the outer peripheral surface of the metal connecting piece, so that the welding of the pole and the sealing of the aluminum plastic film are respectively carried out on different parts (the cover plate substrate and the metal connecting piece) of the composite cover plate, and compared with the case that the soft package battery is welded with the pole lug along the length direction of the battery core and is thermally fused and sealed through the pole lug and the aluminum plastic film, when the composite cover plate disclosed by the utility model is used, the occupied space of the composite cover plate along the length direction of the battery core is smaller, and the space utilization rate and the energy density of a battery cell are further improved;

3. compared with the traditional square battery, the composite cover plate is used for sealing the aluminum plastic film, and when the internal air pressure of the battery is high, the hot melting connection part of the aluminum plastic film and the metal connecting piece can be opened for pressure relief under the action of pressure, so that an explosion-proof valve is not required to be arranged on the composite cover plate; and different from the traditional square battery in the form of injecting liquid through the liquid injection hole, the composite cover plate can heat-seal the aluminum plastic film after the liquid injection is finished, so that the liquid injection hole is not required to be reserved on the composite cover plate, the liquid injection speed is higher, the structure is simpler, and the cost is lower.

Furthermore, the metal connecting piece is provided with a groove which is sunken towards the direction of the battery cell, and the groove is arranged around the cover plate substrate. The size of the outer peripheral surface of the metal connecting piece along the length direction of the battery core can be increased on the premise that the overall length size of the battery is not increased through the arrangement of the grooves, so that the size of the tab adhesive (along the length direction of the battery core) on the outer peripheral surface of the metal connecting piece can be increased to some extent, the seal length of the aluminum plastic film hot melting is increased, and the packaging strength and the sealing effect of the aluminum plastic film and the metal connecting piece are ensured. In addition, the groove arranged around the cover plate substrate enables the metal connecting piece to form closed type surrounding on the cover plate substrate, so that the outer peripheral surface of the metal connecting piece can form closed type surrounding on the cover plate substrate, and the sealing effect of the composite cover plate can be achieved when the aluminum plastic film is thermally fused on the outer peripheral surface of the metal connecting piece.

It should be noted that the recess degree of the recess should not affect the internal space of the battery cell, that is, when the battery cell is located in the aluminum plastic film, one end of the recess facing the battery cell will not squeeze the battery cell.

Further, the metal connecting piece comprises an inner ring side plate and an outer ring side plate, wherein one ends of the inner ring side plate and the outer ring side plate facing the direction of the battery cell are connected through a bottom plate, and grooves are formed among the inner ring side plate, the outer ring side plate and the bottom plate; and one side of the outer ring side plate, which is far away from the inner ring side plate, is coated with tab glue. The grooves facing the direction of the battery cells are formed by matching the inner ring side plate, the outer ring side plate and the bottom plate, so that the packaging strength of the aluminum plastic film and the metal connecting piece is improved; one side of the outer ring side plate, which is far away from the inner ring side plate, is used as the outer circumferential surface of the metal connecting piece, and the tab glue coated on the outer ring side plate can realize hot melting connection with the aluminum plastic film.

Furthermore, one end of the inner ring side plate, which is far away from the battery cell, is bent towards the direction far away from the outer ring side plate to form a connecting plate connected with the cover plate substrate. Through the setting of connecting plate, both realized the connection of inner ring curb plate and apron base plate, can make between inner ring curb plate and the apron base plate keep the interval again to reserve sufficient installation space for the electric core.

Furthermore, one end of the inner ring side plate far away from the battery cell direction is abutted on the lower end face of the cover plate substrate, and the distance between the cover plate substrate and the outer ring side plate is smaller than the distance between the inner ring side plate and the outer ring side plate along the width direction of the battery cell. The inner ring side plate can play the role of connecting and supporting the cover plate substrate, the cover plate substrate can extend a distance to the direction of the outer ring side plate relative to the inner ring side plate through setting the distance between the cover plate substrate, the outer ring side plate and the inner ring side plate, a containing space can be formed between the cover plate substrate, the inner ring side plate and the bottom plate through setting the distance between the cover plate substrate, the outer ring side plate and the inner ring side plate, and in the subsequent formation or capacity division process of a battery, direct extrusion damage to a battery core caused by extrusion of a test terminal of test equipment to a pole can be counteracted by arranging a tool in the containing space, namely, the supporting force to the cover plate substrate and the pole is enhanced through arranging the tool, and then the extrusion force of the test terminal to the pole is counteracted.

Further, the size of the outer ring side plate along the length direction of the battery cell is larger than that of the inner ring side plate along the length direction of the battery cell, so that the size of the outer ring side plate along the length direction of the battery cell is increased as much as possible, the size of the tab adhesive part which can be coated on the outer ring side plate is further increased, and the hot-melt seal length of the tab adhesive and the aluminum plastic film is increased.

Furthermore, one end of the outer ring side plate far away from the battery cell direction is slightly higher than the cover plate substrate. The problem that the battery space utilization ratio is reduced because of the space occupation of the outer ring side plate in the length direction of the battery core is reduced is solved by setting one end of the outer ring side plate to be slightly higher than the cover plate substrate based on the consideration of increasing the hot melting seal length of the aluminum plastic film, so that the outer ring side plate is only slightly higher than the cover plate substrate when being arranged, and the effect of optimizing and improving the length dimension of the outer ring side plate can be realized by increasing the hot melting length of the aluminum plastic film and mainly relying on the dimension growth of the outer ring side plate, which is brought by a groove, along the length direction of the battery core, and setting one end of the outer ring side plate, which is far away from the direction of the battery core, to be slightly higher than the cover plate substrate. In addition, the end of the outer ring side plate far away from the direction of the battery core is required to be lower than or flush with the top end of the pole, so that the influence on the whole length dimension of the battery is reduced as much as possible.

Furthermore, the tab adhesive is partially or fully coated on one side of the outer ring side plate far away from the inner ring side plate along the length direction of the battery cell. The partial coating means that the tab glue does not completely coat the outer ring side plate along the length direction of the battery cell, namely the dimension of the tab glue along the length direction of the battery cell is smaller than the dimension of the outer ring side plate along the length direction of the battery cell; all coating means that the tab glue completely coats the outer ring side plate along the length direction of the battery cell, that is, the dimension of the tab glue along the length direction of the battery cell is equal to the dimension of the outer ring side plate along the length direction of the battery cell.

It should be noted that, whether the outer circumferential surface of the outer ring side plate in the width direction of the cell is partially coated or fully coated, the outer circumferential surface of the outer ring side plate is completely coated with the tab adhesive, that is, the tab adhesive is coated on the outer circumferential surface of the outer ring side plate in a closed loop shape.

Further, one end of the metal connecting piece facing the direction of the battery cell is lower than the pole.

Further, the metal connecting piece and the cover plate substrate are integrally formed or welded and fixed.

The second technical scheme adopted by the utility model is as follows: a battery cell comprises

A battery cell;

the composite cover plate is covered on one end of the battery cell along the length direction; the composite cover plate adopts any one of the composite cover plates;

the aluminum plastic film is coated on the battery core, and one end of the aluminum plastic film along the length direction of the battery core can extend out of the battery core and is connected with the outer peripheral surface of the metal connecting piece through the tab adhesive in a hot melting mode.

The battery monomer has the beneficial effects that:

1. the composite cover plate is used as a sealing piece, the aluminum plastic film is used as a shell to wrap the battery cell, so that the battery cell can be protected, the effect of isolating external water vapor can be achieved, and the sealing effect of the battery cell can be ensured by the hot melt connection of the tab adhesive and the aluminum plastic film; the battery unit has the advantages of square batteries and soft package batteries, ensures the overcurrent capacity of high-current charge and discharge, and simultaneously ensures that the inside of the aluminum plastic film can be kept in a negative pressure state, so that the positive electrode plate and the negative electrode plate of the battery cell positioned in the aluminum plastic film can be tightly attached, the charge transfer in the charge and discharge process is facilitated, and the ion migration among the electrode plates of the battery cell and the high-current charge and discharge effect are improved;

2. compared with the traditional soft-package battery, the battery cell is sealed by the composite cover plate and the aluminum plastic film in a hot-melting way, so that the aluminum plastic film does not need to be punched, the battery cell thickness of the soft-package battery is prevented from being limited by the depth of the aluminum plastic film punched pit, and the processing of a thick-size battery cell is facilitated; and the welding and sealing are respectively carried out on different parts (a cover plate substrate and a metal connecting piece) of the composite cover plate, compared with the welding of the tab of the soft package battery along the length direction of the battery core and the hot-melting sealing of the tab and the aluminum plastic film, the occupied space of the battery cell along the length direction of the battery core is smaller, the space utilization rate is higher, and the energy density of the battery cell is improved;

3. compared with the traditional square battery, when the internal air pressure of the battery is higher, the hot melt connection part of the aluminum plastic film and the metal connecting piece can be opened for pressure relief under the action of pressure, so that an explosion-proof valve is not required to be additionally arranged; the battery monomer can be used for injecting liquid into the aluminum plastic film through the air bag, and the aluminum plastic film is heat-sealed after the liquid injection is completed, so that no additional liquid injection holes are needed, parts are saved, the cost is reduced, the liquid injection speed is higher, and the efficiency is higher.

Further, the battery cell comprises a battery cell body and a battery cell tab arranged on the battery cell body, and the battery cell tab is electrically connected with the pole. The diversion effect on the battery cell is realized through the electric connection of the pole post and the battery cell pole lug.

Further, the metal connecting piece comprises an inner ring side plate and an outer ring side plate, and one ends of the inner ring side plate and the outer ring side plate facing the direction of the battery cell are connected through a bottom plate; one end of the inner ring side plate far away from the battery cell direction is abutted on the lower end face of the cover plate substrate, and the distance between the cover plate substrate and the outer ring side plate is smaller than the distance between the inner ring side plate and the outer ring side plate along the width direction of the battery cell.

The inner ring side plate can play the role of connecting and supporting the cover plate substrate, and the cover plate substrate can extend out of a distance from the inner ring side plate to the outer ring side plate through setting the intervals among the cover plate substrate, the outer ring side plate and the inner ring side plate, so that a containing space can be formed among the cover plate substrate, the inner ring side plate and the bottom plate, and in the subsequent formation or capacity division process of the battery, direct extrusion damage to the battery core caused by extrusion of the testing terminal of the testing equipment can be counteracted by arranging a tool in the containing space.

The third technical scheme adopted by the utility model is as follows: a power battery comprises a plurality of battery cells.

The utility model adopts the technical scheme that: the power device comprises the power battery, wherein the power battery is used for providing electric energy.

Drawings

FIG. 1 is a schematic perspective view of a composite cover plate according to an embodiment of the present utility model;

FIG. 2 is a top view of a composite cover plate according to an embodiment of the present utility model;

FIG. 3 is a schematic view in section in the direction A-A of FIG. 2;

FIG. 4 is a schematic cross-sectional view of a metal connector with a connecting plate removed according to an embodiment of the present utility model;

FIG. 5 is a schematic cross-sectional view of an assembled composite cover plate and aluminum plastic film according to an embodiment of the present utility model;

fig. 6 is a partial enlarged view of the portion B in fig. 5.

In the figure:

1-a cover plate substrate;

2-metal connectors; 21-grooves; 22-inner ring side plates; 23-an outer ring side plate; 24-a bottom plate; 25-connecting plates;

3-tab glue;

4-pole;

5-aluminum plastic film.

Detailed Description

The preferred embodiments of the present utility model will be described in detail below with reference to the accompanying drawings so that the advantages and features of the present utility model can be more easily understood by those skilled in the art, thereby making clear and defining the scope of the present utility model.

It should be noted that all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model; the terms "comprising" and "having" and any variations thereof in the description of the utility model and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion.

In the description of the present utility model, terms of directions or positional relationships indicated by terms such as "upper", "lower", "top", "bottom", "length", "width", "thickness", and the like are based on directions or positional relationships shown in the drawings, and terms such as "inner" and "outer" refer to directions toward or away from a geometric middle of a specific part, respectively, which are merely for convenience of description, and do not indicate or imply that the apparatus or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

It should also be noted that, in the description of the present utility model, unless explicitly specified and limited otherwise, the terms "disposed," "configured," "mounted," "connected," "secured" and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through other components; either mechanically or electrically. The specific meaning of the above terms in the present utility model can be understood by those skilled in the art according to the specific circumstances. Furthermore, the drawings are in a very simplified form and non-precise ratios are employed, simply to facilitate a clear and thorough description of the embodiments of the present utility model.

Furthermore, references to "an embodiment" in the present disclosure mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present disclosure. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

Examples

Referring to fig. 1-3, the composite cover plate comprises a cover plate substrate 1, a metal connecting piece 2 and tab glue 3, wherein a pole 4 is arranged on the cover plate substrate 1; the metal connector 2 is connected with the cover board substrate 1, and the metal connector 2 has an outer peripheral surface arranged around the cover board substrate 1; the tab glue 3 is coated on the outer peripheral surface of the metal connecting piece 2 and is used for being connected with the aluminum plastic film 5 in a hot melting mode.

When the battery cell is used, the composite cover plate is used as a sealing piece, when the battery cell is applied to a battery cell, the pole 4 is electrically connected with a battery cell (not shown in the figure), so that the pole 4 is used as a current conducting channel, and the lug adhesive 3 on the outer peripheral surface of the metal connecting piece 2 is connected with the aluminum plastic film 5 in a hot melting way, so that the battery cell positioned in the aluminum plastic film 5 is sealed; the arrangement makes the battery monomer have the advantages of square batteries and soft package batteries, namely, the high overcurrent capacity of the pole column 4 is utilized to ensure the high multiplying power performance of the battery monomer, and meanwhile, the negative pressure state inside the aluminum plastic film 5 is utilized to make the multi-layer pole pieces of the battery cell tightly attached, so that the charge transfer in the charge and discharge process is facilitated, and the ion migration and the heavy current charge and discharge effect between the pole pieces of the battery cell are improved.

In the composite cover plate, the aluminum plastic film 5 is directly connected with the outer peripheral surface of the metal connecting piece 2 in a hot melting way, so that pit punching of the aluminum plastic film 5 is not needed, the limitation of the pit punching depth of the aluminum plastic film 5 on the thickness of the battery cell is avoided, and the processing of the battery cell with a thick size is realized; in addition, the pole 4 is arranged on the cover plate substrate 1, and the aluminum plastic film 5 is thermally fused on the outer peripheral surface of the metal connecting piece 2, so that the welding of the pole 4 and the sealing of the aluminum plastic film 5 are respectively carried out on different parts (the cover plate substrate 1 and the metal connecting piece 2) of the composite cover plate, and compared with the soft package battery, the method has the advantages that the pole lugs are welded along the length direction of the battery core and thermally fused and sealed through the pole lugs and the aluminum plastic film, when the composite cover plate of the embodiment is used, the occupied space of the composite cover plate along the length direction of the battery core is smaller, and the space utilization rate and the energy density of a battery cell are improved;

when the internal air pressure of the battery is higher, the hot melt connection part of the aluminum plastic film 5 and the metal connecting piece 2 can be opened under the pressure effect, so that the aim of pressure relief is fulfilled, and an explosion-proof valve is not required to be additionally arranged on the composite cover plate; and be different from traditional square battery through annotating the form of liquid hole annotating the liquid, the compound apron of this embodiment is after being connected with plastic-aluminum membrane 5, and the accessible air pocket annotates liquid to plastic-aluminum membrane 5 is inside to carry out the heat-seal to plastic-aluminum membrane 5 again after annotating the liquid and accomplish, consequently, need not to reserve the notes liquid hole on compound apron, when saving spare part, reduce cost, simplify the structure of compound apron, annotate liquid speed faster moreover, efficiency is higher.

It should be noted that, the shape of the composite cover plate in the present embodiment is the shape of the cover plate in the square battery, wherein the cover plate substrate 1 is a square plate body, the metal connecting piece 2 is a hollow square plate body, and the composite cover plate formed by connecting the cover plate substrate 1 and the metal connecting piece 2 is also a square plate body.

In order to improve the packaging strength of the battery cell, in some embodiments, referring to fig. 2-3, the metal connector 2 is provided with a groove 21 recessed toward the battery cell, and the groove 21 is disposed around the cover substrate 1.

Through set up on metal connection piece 2 towards the sunken recess 21 of electric core direction can increase the size of electric core length direction of metal connection piece 2 outer peripheral face to the size of electric core length direction is followed to the utmost point ear glue 3 that is located on the metal connection piece 2 outer peripheral face in the increase, and then is convenient for increase the seal length of plastic-aluminum membrane 5 and utmost point ear glue 3 hot melt, guarantees the encapsulation intensity and the sealed effect to electric core after plastic-aluminum membrane 5 and metal connection piece 2 hot melt connection. In addition, the metal connecting piece 2 can form a closed type surrounding to the cover board substrate 1 through the groove 21 arranged around the cover board substrate 1, so that the outer peripheral surface of the metal connecting piece 2 can form a closed type surrounding to the cover board substrate 1, and the sealing effect on the composite cover board can be realized when the aluminum plastic film 5 is thermally fused on the outer peripheral surface of the metal connecting piece 2.

It should be noted that, the recess 21 of the metal connecting piece 2 should not squeeze the battery cell on the premise that the recess 21 does not affect the internal space of the battery cell, i.e. when the battery cell is assembled into the aluminum plastic film 5, so as to ensure the normal assembly of the battery cell.

Specifically, referring to fig. 3, the metal connector 2 includes an inner ring side plate 22 and an outer ring side plate 23, wherein one ends (lower ends in the drawing) of the inner ring side plate 22 and the outer ring side plate 23 toward the cell direction are connected by a bottom plate 24, and a groove 21 is formed between the inner ring side plate 22, the outer ring side plate 23 and the bottom plate 24. And one side of the outer ring side plate 23 far away from the inner ring side plate 22 is coated with tab adhesive 3. Therefore, the side of the outer ring side plate 23 away from the inner ring side plate 22 is the outer circumferential surface of the metal connector 2.

The grooves 21 facing the direction of the battery cells are formed by matching the inner ring side plate 22, the outer ring side plate 23 and the bottom plate 24, so that the packaging strength of the aluminum plastic film 5 and the metal connecting piece 2 is improved; wherein, one side of the outer ring side plate 23 far away from the inner ring side plate 22 is used as the outer circumferential surface of the metal connecting piece 2, and the tab glue 3 coated on the outer ring side plate can realize hot melting connection with the aluminum plastic film 5.

In some embodiments, the bottom plate 24 is disposed along the width direction of the battery cell and has a hollow square plate structure, the inner side wall of the bottom plate 24 is connected with one end of the inner ring side plate 22, and the outer side wall is connected with one end of the outer ring side plate 23. Further, the outer ring side plate 23 and the inner ring side plate 22 are disposed along the length direction of the battery cell, and the center of the outer ring side plate 23 coincides with the projection of the center of the inner ring side plate 22 in the length direction of the battery cell.

In the groove 21 structure of the metal connecting piece 2, the bottom plate 24 is used as the lower end surface of the groove 21, when the bottom plate 24 is arranged along the width direction of the battery cell, the bottom plate 24 can be parallel to the battery cell arranged in the aluminum plastic film 5, so that equal distances can be kept between any position of the bottom plate 24 and the battery cell, the bottom plate 24 can maximally approach to the battery cell on the premise of not extruding the battery cell, and the length dimension of the outer ring side plate 23 is increased.

In some embodiments, the end of the inner ring side plate 22 remote from the cell direction (the upper end of the inner ring side plate in the drawing) is connected to the cover substrate 1.

It should be noted that the inner ring side plate 22 is actually provided to realize the recession of the metal connector 2, so that, when in installation, an end of the inner ring side plate 22 away from the cell direction (an upper end of the inner ring side plate 22 in the drawing) may be set to be flush with an end of the cover substrate 1 toward the cell direction (a lower end of the cover substrate in the drawing), so as to reduce the material required for the inner ring side plate 22 as much as possible, thereby achieving the purpose of saving cost.

Further, one end of the inner ring side plate 22 (upper end of the inner ring side plate in the drawing) far from the cell direction is bent and provided with a connecting plate 25 in a direction far from the outer ring side plate 23, the connecting plate 25 is arranged along the cell width direction, one end of the connecting plate is connected with one end of the inner ring side plate 22 far from the cell direction, and the other end of the connecting plate is connected with one end of the cover plate substrate 1 facing the cell direction (namely, the connecting plate 25 is connected with the upper end of the inner ring side plate 22 and the lower end of the cover plate substrate 1). The connection of the inner ring side plate 22 and the cover plate base plate 1 is realized by the arrangement of the connecting plate 25.

In some embodiments, the inner ring side plate 22, the bottom plate 24, the outer ring side plate 23, and the connecting plate 25 are integrally formed.

In the process of battery formation and capacity division, the test terminal of the test equipment can apply extrusion force towards the direction of the battery cell to the pole, so that the battery cell is possibly damaged. Therefore, in some embodiments, in order to improve the supporting force of the cover substrate 1, the structure of the metal connector 2 is adjusted: referring to fig. 4, the connecting plate 25 is removed, and the upper end of the inner ring side plate 22 is directly abutted against the lower end face of the cover plate substrate 1; and the cover plate base plate 1 is extended a distance from the inner ring side plate 22 to the outer ring side plate 23. I.e. the spacing between the cover plate base plate 1 and the outer ring side plate 23 is smaller than the spacing between the inner ring side plate 22 and the outer ring side plate 23. The setting makes and can form a accommodation space between apron base plate 1, inner ring curb plate 22, bottom plate 24 like this, at the in-process of battery follow-up formation or partial volume, through lay the frock in the accommodation space increase to the holding power of apron base plate 1, and then offset test equipment's test terminal to the extrusion force of utmost point post, avoid the direct extrusion damage to the electric core. It should be noted that the inner ring side plate 22 and the cover plate substrate 1 may be integrally formed or welded and fixed.

In some embodiments, as shown in fig. 5, the dimension of the outer ring side plate 23 along the length direction of the battery core is larger than the dimension of the inner ring side plate 22 along the length direction of the battery core, so as to increase the dimension of the outer ring side plate 23 along the length direction of the battery core as much as possible, further increase the dimension of the part of the outer ring side plate 23, which can be coated with the tab adhesive 3, and facilitate increasing the hot-melt seal length of the tab adhesive 3 and the aluminum plastic film 5.

Because the bottom plate 24 is arranged along the width direction of the cell, the lower end surfaces of the outer ring side plate 23 and the inner ring side plate 22 are flush, when the dimension of the outer ring side plate 23 along the length direction of the cell is larger than that of the inner ring side plate 22 along the length direction of the cell, the upper end surface of the outer ring side plate 23 can be higher than the upper end surface of the inner ring side plate 22, and because the upper end surface of the inner ring side plate 22 is flush with the lower end surface of the cover plate substrate 1, the dimension of part of the outer ring side plate 23 along the length direction of the cell can be offset by utilizing the height of the cover plate substrate 1, so that the space occupation of the outer ring side plate along the length direction of the cell is reduced as much as possible.

Further, the end of the outer ring side plate 23 away from the cell direction is slightly higher than the cover substrate 1. The arrangement of the outer ring side plate 23 with one end higher than the cover plate substrate 1 is also based on the consideration of increasing the hot-melting seal length of the aluminum plastic film 5, but in order to reduce the problem of the reduction of the battery space utilization rate caused by the space occupation of the outer ring side plate 23 in the length direction of the battery core, the outer ring side plate 23 is only slightly higher than the cover plate substrate 1 when in arrangement, so that the problem can be understood that the increase of the hot-melting seal length of the aluminum plastic film 5 mainly depends on the increase of the dimension of the outer ring side plate 23 along the length direction of the battery core, which is brought by the groove 21, and the arrangement of one end of the outer ring side plate 23 far away from the battery core direction is slightly higher than the cover plate substrate 1, so that the effect of optimizing and improving the length dimension of the outer ring side plate 23 can be only achieved.

It should be noted that the end of the outer ring side plate 23 away from the cell is also required to be lower than the top end of the pole 4 or flush with the top end of the pole 4, so as to reduce the influence of the outer ring side plate 23 on the overall length dimension of the battery as much as possible.

In some embodiments, the tab adhesive 3 is partially or fully coated on the side of the outer ring side plate 23 remote from the inner ring side plate 22.

It should be noted that, as shown in fig. 1 and 3, the partial coating in the present embodiment means that the tab adhesive 3 does not completely coat the outer ring side plate 23 along the length direction of the battery cell, that is, the dimension of the tab adhesive 3 along the length direction of the battery cell is smaller than the dimension of the outer ring side plate 23 along the length direction of the battery cell; all coating means that the tab adhesive 3 completely coats the outer ring side plate 23 along the length direction of the battery cell, that is, the dimension of the tab adhesive 3 along the length direction of the battery cell is equal to the dimension of the outer ring side plate 23 along the length direction of the battery cell. Whether the outer ring side plate 23 is partially coated or fully coated, the outer circumferential surface of the cell in the width direction is completely coated with the tab adhesive 3, that is, the tab adhesive 3 is coated on the outer circumferential surface of the outer ring side plate 23 in a closed loop.

Further, when the tab adhesive 3 is partially coated on one side of the outer ring side plate 23 far away from the inner ring side plate 22, the tab adhesive 3 is coated on the upper end side wall of the outer ring side plate 23, so that when the aluminum plastic film 5 is hot-melted on the outer ring side plate 23, the aluminum plastic film can keep sealing with the upper end side wall of the outer ring side plate 23, and the phenomenon of scattering at the edge of the aluminum plastic film 5 is avoided.

In some embodiments, the end of the metal connector 2 facing in the cell direction is lower than the end of the pole 4 facing in the cell direction.

In some embodiments, the metal connector 2 and the cover substrate 1 may be integrally formed or welded.

In some embodiments, the pole 4 is disposed on the cover substrate 1 in a penetrating manner, and is welded and fixed with the cover substrate 1. In practical design, only one pole 4, which may be a positive pole or a negative pole, may be provided on one cover substrate 1. Alternatively, the positive electrode post and the negative electrode post may be integrated on one cover substrate 1 at the same time, that is, two electrode posts 4 are disposed on one cover substrate 1, and the two electrode posts 4 are respectively the positive electrode post and the negative electrode post.

It should be noted that the material of the cover substrate 1 is not particularly limited, and conventional aluminum metal may be used. The metal connecting piece 2 needs to ensure structural strength and connection strength with the cover plate substrate 1, and the outer ring side plate 23 of the metal connecting piece 2 needs to have stronger sealing strength with the tab glue, namely the outer ring side plate is easy to cover the tab glue and can be tightly attached to the tab glue.

Referring to fig. 5-6, the utility model also provides a battery cell, which comprises a battery cell, a composite cover plate and an aluminum plastic film, wherein the composite cover plate is covered on one end of the battery cell along the length direction; the aluminum plastic film is coated on the battery core, and one end of the aluminum plastic film along the length direction of the battery core can extend out of the battery core and is connected with the outer peripheral surface of the composite cover plate through the lug adhesive in a hot melting way. Wherein, the compound apron adopts aforesaid compound apron.

When the composite cover plate is applied to the battery cell of the embodiment, the battery cell is wrapped by the aluminum plastic film serving as the shell, and the composite cover plate serving as the sealing piece, so that the battery cell of the embodiment can have the advantages of a square battery and a soft package battery, and the negative pressure state can be kept in the aluminum plastic film while the overcurrent capacity of high-current charge and discharge is ensured, so that the positive electrode plate and the negative electrode plate of the battery cell in the aluminum plastic film can be tightly attached, the charge transfer in the charge and discharge process is facilitated, and the ion migration between the pole pieces of the battery cell and the high-current charge and discharge effect are improved;

compared with the traditional soft-package battery, the battery cell of the embodiment is sealed by the composite cover plate and the aluminum plastic film in a hot-melting way, so that the aluminum plastic film does not need to be punched, the thickness of the battery cell of the soft-package battery is prevented from being limited by the depth of the punching pit of the aluminum plastic film, and the processing of the thick-size battery cell is facilitated; and the welding and sealing are respectively carried out on different parts (a cover plate substrate and a metal connecting piece) of the composite cover plate, compared with the welding of the tab of the soft package battery along the length direction of the battery core and the hot-melting sealing of the tab and the aluminum plastic film, the occupied space of the battery cell along the length direction of the battery core is smaller, the space utilization rate is higher, and the energy density of the battery cell is improved;

compared with the traditional square battery, when the internal air pressure of the battery is high, the hot melt connection part of the aluminum plastic film and the metal connecting piece can be opened for pressure relief under the action of pressure, so that an explosion-proof valve is not required to be additionally arranged; the battery monomer can be used for injecting liquid into the aluminum plastic film through the air bag, and the aluminum plastic film is heat-sealed after the liquid injection is completed, so that no additional liquid injection holes are needed, parts are saved, the cost is reduced, the liquid injection speed is higher, and the efficiency is higher.

In some embodiments, the battery cell includes a battery cell body and a battery cell tab disposed on the battery cell body, the battery cell tab being electrically connected to the post. The diversion effect on the battery cell is realized through the electric connection of the pole post and the battery cell pole lug. And the polar post is used as a current diversion channel, so that the overcurrent capacity of high-current charge and discharge can be ensured, and the high-rate performance of the battery monomer is further ensured.

The utility model also provides a power battery which comprises a plurality of battery monomers, wherein the battery monomers can be connected in series or in parallel or in series-parallel connection. The series-parallel connection refers to that a plurality of battery monomers are connected in series or in parallel. The plurality of battery monomers can be directly connected in series or in parallel or in series-parallel, and then the whole formed by the plurality of battery monomers is accommodated in the box body; or a plurality of battery monomers are firstly connected in series or in parallel or in series-parallel connection to form a plurality of battery modules, and then the plurality of battery modules are connected in series or in parallel or in series-parallel connection to form a whole and are accommodated in the box body. In addition, the power cell may include other structures, such as a bus member, for making electrical connection between the plurality of battery cells.

The utility model also provides an electric device which comprises the power battery, wherein the power battery is used for providing electric energy. The electric device is usually a vehicle, the vehicle can be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extending vehicle. The power battery is arranged in the vehicle, can be at the bottom or the head or the tail of the vehicle, and is used for supplying power to the vehicle.

The above embodiments are only for illustrating the technical concept and features of the present utility model, and are intended to enable those skilled in the art to understand the content of the present utility model and to implement the same, but are not intended to limit the scope of the present utility model, and all equivalent changes or modifications made according to the spirit of the present utility model should be included in the scope of the present utility model.

Claims (14)

1. A composite cover plate, characterized in that: comprising

A cover plate substrate provided with a pole;

a metal connector connected with the cover plate substrate, and having an outer peripheral surface disposed around the cover plate substrate; the outer peripheral surface is used for coating tab glue, and the tab glue is used for being connected with the aluminum plastic film in a hot melting mode.

2. The composite cover sheet of claim 1, wherein: the metal connecting piece is provided with a groove which is sunken towards the direction of the battery cell, and the groove is arranged around the cover plate substrate.

3. The composite cover sheet of claim 2, wherein: the metal connecting piece comprises an inner ring side plate and an outer ring side plate, wherein one ends of the inner ring side plate and the outer ring side plate facing the direction of the battery cell are connected through a bottom plate, and the inner ring side plate, the outer ring side plate and the bottom plate form the groove together; and one side of the outer ring side plate, which is far away from the inner ring side plate, is used for coating the tab adhesive.

4. A composite cover sheet according to claim 3, wherein: and one end, far away from the battery cell direction, of the inner ring side plate is bent towards the direction, far away from the outer ring side plate, to form a connecting plate connected with the cover plate substrate.

5. A composite cover sheet according to claim 3, wherein: and one end, far away from the battery cell direction, of the inner ring side plate is abutted to the lower end face of the cover plate substrate, and the distance between the cover plate substrate and the outer ring side plate is smaller than the distance between the inner ring side plate and the outer ring side plate along the width direction of the battery cell.

6. A composite cover sheet according to claim 3, wherein: the size of the outer ring side plate along the length direction of the battery cell is larger than that of the inner ring side plate along the length direction of the battery cell.

7. A composite cover sheet according to claim 3, wherein: and one end of the outer ring side plate, which is far away from the battery cell direction, is higher than the cover plate substrate.

8. A composite cover sheet according to claim 3, wherein: the tab adhesive is partially or fully coated on one side, far away from the inner ring side plate, of the outer ring side plate along the length direction of the battery cell.

9. The composite cover sheet according to any one of claims 1-8, wherein: the metal connecting piece and the cover plate substrate are integrally formed or welded and fixed.

10. A battery cell, characterized in that: comprising

A battery cell;

the composite cover plate of any one of claims 1-9, being capped on one end of the cell along its length;

the aluminum plastic film is coated on the battery cell; and one end of the battery cell along the length direction of the battery cell can extend out of the battery cell and is connected with the outer peripheral surface of the metal connecting piece through the tab adhesive in a hot melting way.

11. The battery cell of claim 10, wherein: the battery cell comprises a battery cell body and a battery cell tab arranged on the battery cell body, and the battery cell tab is electrically connected with the pole.

12. The battery cell of claim 10, wherein: the metal connecting piece comprises an inner ring side plate and an outer ring side plate, and one ends of the inner ring side plate and the outer ring side plate, which face the direction of the battery cell, are connected through a bottom plate; and one end, far away from the battery cell direction, of the inner ring side plate is abutted to the lower end face of the cover plate substrate, and the distance between the cover plate substrate and the outer ring side plate is smaller than the distance between the inner ring side plate and the outer ring side plate along the width direction of the battery cell.

13. A power cell, characterized in that: comprising a plurality of battery cells according to any one of claims 10-12.

14. An electrical device, characterized in that: a power cell comprising the power cell of claim 13, said power cell configured to provide electrical energy.